Online Examination System database design and deep apologies for food!

Sorry, I thought about the course setting last night and summarized the following mistakes:

1. I did not pay attention to the architecture before,CodeThere is no hierarchy, so this time we use three layers. It took some time before.

2. after a big change in the code, I changed the background to static in one breath. I admit that I read the three-tier example provided by Tao Zi .. the connection string in the data access layer is not stored in the configuration file. I thought of this together with the configuration file that I used to call other projects when I wrote the DLL, so I couldn't read the results from the configuration file...

3. in the past, the course was designed by myself from the database, and the requirements are naturally very clear. This time it comes with its own database. I admit that when I saw the three tables, just as happy as a child, I feel that there is nothing in the background, so I don't need to develop it well, so I think the database is so simple and there is no actual need... however, I ignored one thing. The School of food is different from our school. The students are naturally different. The overall level is much better than ours.

4. From a macro perspectiveProgram, Only focus on the data... we think that the most important thing for such programs is to manipulate data .. however, I am so excited that I ignore a lot of other things, such as object-oriented classes and interfaces. Anyone can say anything. But to understand it well, a lot of coding needs to be done in order to better think about it. I am the legendary cat with high eyes

5. I have always thought that I would not do anything about html CSS and JavaScript on the presentation layer in the future, because I have not completely written anything about the Web Front-end, coupled with the "evil" Asp.net. My failure was caused by it. I didn't know Asp.net, but I have to understand it all the time. dislike. net's Automatic Binding thought it was too dead and we had to write three layers, so I manually bound myself to explore its events. When debugging its properties, it takes a lot of time and page_load to obtain the desired property.
When Ajax is used or Ajax is not used, it will be executed. I have the most errors here, because I always forget to write ispostback .... the second is to bind this binding, which directly bypasses me. For logic reasons, the binding between the bindings makes me feel that the program is not efficient. A small change is to re-change the binding logic. the final result is that the binding logic is quite messy, isn't it too difficult to maintain? At the time of writing, I was always yelling at the TMD Server Control to bind TMD... these are all my mistakes. Due to the hasty construction, my understanding of this problem keeps going. In fact, I should have a good understanding of the operating mechanism of Asp.net .... the result is that I think Web development is not like web development.
All merged into a variety of strange bugs. My mistake!

6. I am too conceited. I am too small to look at the functions that these three tables can bring. I am totally defeated.

7. too sense of responsibility .. I am so sorry for the food. This is the key point. For this reason, I am very guilty. I always say that if you want to learn technology, you must first learn to be a person. But in the end, I find myself the most problematic person.

 

From this point on, I found that I really need to write something completely and independently to integrate my own knowledge and make up for the poor web development front-end of my thief, so I failed from me. I re-built a local online examination system and climbed where I fell! I think this system will take me a lot of time, but my impetuous character is destined for me to go through this battle, in order to grow into a university, I don't expect to receive any projects from the school. I also don't want to report any hope for the development of a group of teams in our school. As a result, I still find that in this environment, everything depends on what you learn. What you learn is that you want to think about what you want to do in this environment.

So I spent half a day looking at the online examination system written by others and then designed the following database based on my own level. Thank you!

First, describe

1. The basic question is of course

2. the User table contains the Internet registrants, students, administrators, and other teachers I may consider using the role table to determine that a user can assume multiple roles. for example, the Administrator may also be a teacher.

3. The student table (student) contains the userid! Click here to make a picture!

4. in the examlist table, a parentid is a tree structure, because I think the question mark of an exam can be level 1 or level 2, level 3 and down are related to the design of the outsourcer. So there is not examlistid in exampaper, but an exampaper in every examlist!

5. There is a test-P and test-D in the main ticket. Which user has made the set of papers? The question ID and his answer are in the ticket. Please make a picture!

 

The following figure shows